PhpStorm 2018.1 Help

Regular Expression Syntax Reference

This section provides a brief summary of regexp syntax that can be helpful for creating search and issue navigation patterns.

RegEx syntax reference

Character

Description

\

Marks the next character as either a special character or a literal. For example:

n matches the character n. "\n" matches a newline character.

The sequence \\ matches \ and \( matches (.

^

Matches the beginning of input.

$

Matches the end of input.

*

Matches the preceding character zero or more times. For example, "zo*" matches either z or zoo.

+

Matches the preceding character one or more times. For example, "zo+" matches zoo but not z.

?

Matches the preceding character zero or one time. For example, a?ve? matches the ve in never.

.

Matches any single character except a newline character.

(subexpression)

Matches subexpression and remembers the match. If a part of a regular expression is enclosed in parentheses, that part of the regular expression is grouped together. Thus a regex operator can be applied to the entire group.

If you need to use the matched substring within the same regular expression, you can retrieve it using the backreference (\num, where num = 1..n).

If you need to refer the matched substring somewhere outside the current regular expression (for example, in another regular expression as a replacement string), you can retrieve it using the dollar sign ($num, where num = 1..n).

If you need to include the parentheses characters into a subexpression, use \( or \).

Matches any word character including underscore. Equivalent to [A-Za-z0-9_].

\W

Matches any non-word character. Equivalent to [^A-Za-z0-9_].

\num

Matches num, where num is a positive integer, denoting a reference back to remembered matches.

For example, (.)\1 matches two consecutive identical characters.

\n

Matches n, where n is an octal escape value. Octal escape values should be 1, 2, or 3 digits long.

For example, \11 and \011 both match a tab character.

\0011 is the equivalent of \001 &1.

Octal escape values should not exceed 256. If they do, only the first two digits comprise the expression. Allows ASCII codes to be used in regular expressions.

\xn

Matches n, where n is a hexadecimal escape value. Hexadecimal escape values must be exactly two digits long.

For example, \x41 matches A. \x041 is equivalent to \x04 &1.

Allows ASCII codes to be used in regular expressions.

\\$

Escapes $.

\l

Changes the case of the next character to the lower case.

\u

Changes the case of the next character to the upper case.

\L

Changes the case of all the subsequent characters up to \E to the lower case.

\U

Changes the case of all the subsequent characters up to \E to the upper case.

Tips and Tricks

PhpStorm provides intention actions to check validity of the regular expressions, and edit regular expressions in a scratchpad. Place the caret at a regular expression, and press Alt+Enter. The suggestion list of intention actions, available in this context, appears:

Choose Check RegExp, and press Enter. The dialog box that pops up, shows the current regular expression in the upper pane. In the lower pane, type the string to which this expression should match. If the regular expression matches the entered string, the background becomes green. If the regular expression doesn't match, then the background is red.

Choose Edit RegExp Fragment, and press Enter. The regular expression opens for editing in a separate tab in the editor. However, this is but a scratchpad, and no file is physically created:

As you type in the scratchpad, all changes are synchronized with the original regular expression. Press Escape to close the editor tab.